Type checking behavior for MAGNITUDE

Type checking for MAGNITUDE causes the assembler to perform magnitude validation of signed immediate-data fields of machine instruction operands. To disable the checking, use the NOMAGNITUDE suboption.

For each violation, a warning message (severity 4) is issued and object code is created.

For a 16-bit signed immediate-data field, the normal allowed range of values is -32768 through to 32767.

For a 32-bit signed immediate-data field, the normal allowed range of values is -2147483648 through to 2147483647.

Figure 1 shows the assembler behavior, with the default of MAGNITUDE, which is to issue a warning message and to generate the object code.

Figure 1. MAGNITUDE behavior

00000000 A72A 8000               00008000     12          AHI     R2,32768
** ASMA320W Immediate field operand may have incorrect sign or magnitude
00000004 A72A 7FFF               00007FFF     13          AHI     R2,32767
00000008 A72A 0001               00000001     14          AHI     R2,1
0000000C A72A 0000               00000000     15          AHI     R2,0
00000010 A72A FFFF               FFFFFFFF     16          AHI     R2,-1
00000014 A72A 8000               FFFF8000     17          AHI     R2,-32768
00000018 A72A 7FFF               FFFF7FFF     18          AHI     R2,-32769
** ASMA320W Immediate field operand may have incorrect sign or magnitude
0000001C A72A FFFF               0000FFFF     19          AHI     R2,X'FFFF'
** ASMA320W Immediate field operand may have incorrect sign or magnitude

Note: When generating object code, the assembler takes bits 16 to 31 of Addr2 for use as the immediate-data field. Bits 0 to 15 are ignored.

Figure 2 shows the assembler behavior, with NOMAGNITUDE, which is to issue no messages and to generate the object code.

Figure 2. NOMAGNITUDE behavior

00000000 A72A 8000               00008000     12          AHI     R2,32768
00000004 A72A 7FFF               00007FFF     13          AHI     R2,32767
00000008 A72A 0001               00000001     14          AHI     R2,1
0000000C A72A 0000               00000000     15          AHI     R2,0
00000010 A72A FFFF               FFFFFFFF     16          AHI     R2,-1
00000014 A72A 8000               FFFF8000     17          AHI     R2,-32768
00000018 A72A 7FFF               FFFF7FFF     18          AHI     R2,-32769
0000001C A72A FFFF               0000FFFF     19          AHI     R2,X'FFFF'

Note: When generating object code, the assembler takes bits 16 to 31 of Addr2 for use as the immediate-data field. Bits 0 to 15 are ignored.